watanabe akio, shishigaya touka, grisaia (series), grisaia phantom trigger, official art, second-party source, 1girl, ahoge, bed sheet, black bra, blush, bra, breasts, character name, cleavage, closed mouth, collared shirt, dated, earrings, embarrassed, grey hair, hair between eyes, hand on own face, happy birthday, jewelry, lingerie, long hair, looking at viewer, medium breasts, multi-strapped bra, shirt, solo, strap slip, stud earrings, two side up, underwear, upper body, yellow eyes